CAREER: Elucidating Fuel Spray Atomization Physics: Setting a Path for High-Efficiency Clean Combustion

1653687 Genzale该项目将开发一种新的实验方法，用于测量实际燃烧相关环境下的燃油喷雾特性。这项工作对于高效清洁燃烧发动机的发展至关重要。这些测量结果将我们对燃油喷雾的理解从经验转变为基本，因为在实际燃烧条件下喷雾破碎的物理机制尚未被测量或证明。确定燃油喷雾雾化的控制机制将有助于研究人员开发更精确的计算机模型，这些模型将被用作发现新的高效清洁燃烧策略的预测工具。该项目的教育活动旨在鼓励妇女更广泛地参与研究事业，并培养一支能够创新未来世界所依赖的重大挑战解决方案的多元化工程队伍。1）在燃烧相关条件下测量雾化高压燃料喷雾的联合液滴索特平均直径（SMD）和液体体积分数场，以及2）测试关于导致高压燃料喷雾中的界面不稳定性和射流破碎的物理机制的未经验证的文献假设，包括空气动力、液体湍流、空化和/或孔口流动效应。该研究方法的核心是采用一种新的最先进的高压光学可访问的燃烧室，最近委托我的实验室在格鲁吉亚技术通过机构的支持，使光学喷雾和燃烧测量在高达100巴和900 K。本文提出了一种双波长层析消光测量方法，可以同时测量燃烧相关条件下实际燃油喷雾中液滴表面粗糙度和液体体积分数的三维分布。通过在广泛的环境气体密度条件下测量受控孔几何形状和燃料特性，对燃料喷雾中的雾化机制进行假设检验。

1653687 GenzaleThis project will develop a new experimental method for measuring fuel spray properties under practical combustion-relevant environments. This work is critical for the advancement of high-efficiency clean combustion engines. These measurements stand to transform our understanding of fuel sprays from empirical to fundamental, because the physical mechanisms of spray breakup under practical combustion conditions have yet to be measured or proven. Determination of the governing mechanisms of fuel spray atomization will help researchers develop more accurate computer models, which will be used as a predictive tool for the discovery of new high-efficiency clean combustion strategies. Educational activities in this project aim to encourage broader participation of women in research careers and to develop a diverse engineering workforce who can innovate the grand challenge solutions that our future world will depend on.The primary research objectives of this proposal are to: 1) measure the joint droplet Sauter Mean Diameter (SMD) and liquid volume fraction field of atomized high-pressure fuel sprays under combustion-relevant conditions, and 2) test un-validated literature hypotheses on the physical mechanisms that lead to interface instabilities and jet breakup in high-pressure fuel sprays, including aerodynamic forces, liquid turbulence, cavitation, and/or orifice flow effects. The research approach is centered on the employment of a new state-of-the-art high-pressure optically-accessible combustion chamber recently commissioned within my laboratory at Georgia Tech via institutional support, which enables optical spray and combustion measurements at up to 100 bar and 900 K. A two-wavelength tomographic extinction measurement is developed to enable simultaneous 3-D measurements of droplet SMD and liquid volume fraction distribution in practical fuel sprays under combustion-relevant conditions. Hypothesis testing of the governing atomization mechanisms in fuel sprays is conducted via measurements with controlled orifice geometry and fuel properties over a wide range of ambient gas density conditions.